Some machines, such as the Smith Premier and the Elliott-Fisher, have a carbon roll on their machines for manifolding these duplicate folded bills without handling the carbon paper. These attachments were especially designed for this particular work. After the operator has entered the charges of the three slips for Mrs. J. B. Jackson, or any other customer having more than one slip for the previous day's purchases, she compares the total she has placed on the bill with the total marked on the back of the slips by the auditing department. Fig. 25 shows samples of folded monthly retail bills. The black showing under the top sheet, which is turned over, is the carbon paper used with the bills when made on machines not equipped with the carbon-roll attachment. Some firms place the carbon paper between the sheets at the beginning of the month, and leave it there; others place the carbon paper between the sheets for every charge which is made to the bill. After all the charges have been made, the operator adds up on the adding machine the totals of all the last charges on the various bills to which charges have been made that day. This total must agree with the amount which the auditing department handed over to each bill clerk to be entered upon these bills. The Smith Premier and Elliott-Fisher have tally-strip devices which automatically record the total of each charge made to all the various bills each day. This paper strip, when added up, must agree with the total of the auditing department figures. At the end of the month, about the 26th, most firms begin to total the columns of the bill. The final total of each bill added to the total of every other bill must give a grand total equal to all the charges for the month. This proves that each bill has been correctly added. The balance due from the previous bills is then brought forward, and any payments made during the month deducted, and the bill footed. All credits for returned goods are entered during the month the same as the charges, excepting that they are placed in a separate column provided for that purpose, and deducted at the end of the month from the charges. Some firms post the total charges and credits for the month to the ledger in two lump sums. Other firms prefer to post the total of each day's charges to the ledger daily, instead of letting the posting go until the end of the month. This is a matter to be decided from a bookkeeping standpoint. If the bookkeepers have the current month's charges in the ledger, it saves referring to the bills at the bill clerk's desk for information or the current month's charges. [Illustration: Fig. 25. Monthly Statements of Retail Dry Goods Houses _Remington Typewriter Co._ ] [Illustration: Fig. 26. Smith Premier Device for Inserting Dry Goods Billing Forms Evenly ]